Hi everyone, I have a male betta on his own in a heavily planted 25litre aquarium, he seems very happy and no concerns about him but I have seen a 40 litre aquarium which I wanted to buy for him, what I wanted to know is would that 15 litres make a big difference to him for space or would you leave him in his 25 litre, also would it upset him or stress him out if I moved him to another aquarium, just asking some advice as to what you would do if he was yours, I just think the more space the better for him, thanks